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Ok I think I understand why my Ubuntu 10.10 freezes when pluggin in an external hard drive through USB.

First of all I have to mention that my Ubuntu is installed on another 160gb external hard drive. During the installation it was mounted as /dev/sdc

/dev/sda = primary laptop hard disk with windows 7 /dev/sdb = 4gb usb flash drive used to install ubuntu 10.10 /dev/sdc = my external hard drive where ubuntu had been installed

After performing a System Update and restarting computer, I've received an error message that ubuntu is unable to mount: /boot, /, /home, /windows partitions.

I immediately googled the problem and seems I wasn't the only one with this issue. I've solved the problem by editing /etc/fstab (I don't remembered the exact filename) during the startup console before ubuntu is loaded. I have changed long UUID strings to /dev/sdb/ for all 5 of my partitions. The reason for /dev/sdb is because that was the actual mount showing by typing sudo blkud (again, please edit this post if I have mispelled some commands, as I don't remember exactly what was it called; it shows you the current mount points for every partition that is connected to the computer).

Now whenever I connect my backup external hard drive while ubuntu is loaded, the system just freezes. If I connect it before ubuntu loads, it gives me that same error message I firs received after doing System Update, because now this backup hard drive is pointing to /dev/sdb and my ubuntu external hard drive is pointing to /dev/sdc, while my /etc/fstab file still says that my ubuntu partitions are on /dev/sdb.

So is there any workaround to that? What should I do?

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An output of the following commands would be much appreciated and helpful - sudo blkid , sudo fdisk -l , cat /etc/fstab –  nitstorm Oct 3 '11 at 2:19
    
nitstorm: I will post it tomorrow after work. –  Blue Pony Inc. Oct 3 '11 at 2:30
    
This question appears to be abandoned and unanswered, could you perhaps add more detail to your question? If this question no longer applies then you can either delete it or answer it yourself if you've solved the problem. Thanks! –  Jorge Castro May 16 '12 at 19:06
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I would think the original /etc/fstab file created during Ubuntu install should've worked regardless of the changes in the disk drive device name - it uses UUIDs which were invented exactly for this purpose; UUIDs never change and are unique as their name implies.

So I'm not sure if your original problem was caused by the "bad" /etc/fstab file - at least the partitions mounted using UUIDs should've continued to work.

Now, regarding the freezing - once a device is detected, its name doesn't change - i.e. if your linux partitions were on /dev/sdb during boot, plugging in an external drive won't change the linux drive's name to /dev/sdc, instead, the "another" external drive will be mounted as /dev/sdc, so the system should continue to function.

However, if you plug the "another" drive before booting the machine - it presence may affect the order in which the devices are named, so it may become /dev/sdb or /dev/sdc. Using partition UUIDs or labels is a way to make sure those changes do not affect access to filesystems.

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